If you mean the level 1 fight, he exhausts you early enough. He just...doesn't capitalize on it at all. He exhausts you and runs away like a derp. -.-

If you mean the next one under his turret, I'm betting he did it making the mistake lots of people make: thinking exhaust will reduce how much damage a true damage ability deals (it doesn't). He exhausted right before you ulted probably hoping it would save him from the axe and/or kill you under turret. Sadly, he is a derp and it did neither.

Nononono, when I get home ill find what time is was exactly, but when I catch him leaving mid and just before he reaches the tower just north of their blue he exhausts me like a second before my passive kills him.

There's a difference between tactically targeting a team's most vulnerable member to create openings for winning overall team engagements and playing a 1v1 game without teams. Then you just end up in the situation where, if one player is demonstrably better than the other (or just won in champ select, which can happen), that player ends up steamrolling the other unmercifully.